21NA074

Bulletin No.:
Service Bulletin
Date:
21-NA-074
March, 2021
TECHNICAL
Subject:
Malfunction Indicator Lamp Illuminated On Driver Information Center (DIC) with DTC
P0300 and/or P0299/P2227 Set
Brand:
Model:
Buick
Envision
Model Year:
VIN:
from
to
from
to
2016
2020
-
-
Engine:
Transmission:
Equipped
with 2.0L
Engine
(RPO LTG)
All
Involved Region or Country
United States, Canada
Condition
Some customers may comment on the Malfunction Indicator Lamp illuminated on Driver
Information Center (DIC) or a reduced power complaint.
Technicians may find one or more of the following DTCs set.
• P0300 – Engine Misfire Detected
• P0299 – Engine Underboost
• P2227 – Barometric Pressure (BARO) Sensor Performance
Cause
This condition may be caused by a moisture build up inside the charge air cooler (CAC).
This condition is more likely on the smaller displacement engines where an air-to-air
charge air cooler is used.
In cold temperatures, ambient and PCV moisture can freeze in the charge air cooler,
restricting flow, and causing DTC P0299 and/or P2227, or P0300.
In humid / rainy conditions, ambient moisture can build up in the charge air cooler, and on
a subsequent acceleration be drawn into the engine setting a P0300 and possible
stumble or sag.
Correction
Perform a smoke leak test of the charge air cooler, then follow the repair steps in the
appropriate Service Procedure below, depending on the build date.
Important: DO NOT replace the CAC inlet or outlet
ducts as part of this repair unless there is evidence of
damage and/or a leak from either CAC duct.
Service Procedure - Charge Air Cooler
Diagnosis
Important: Remove the boost sensor and wipe with a
clean rag to remove residual moisture to ensure the
sensor is not contaminated. DO NOT use chemical
cleaners.
1. Perform a smoke leak test of the charge air cooler,
using essential tool GE-52250 Power Smoke
Diagnostic Leak Detector. Refer to Chart Based
Conditions, below, for next steps.
Copyright 2021 General Motors LLC. All Rights Reserved.
Page 2
March, 2021
Bulletin No.: 21-NA-074
Chart Based Conditions
Model
Years
Condition
REPLACE
Charge Air
Cooler –
(CAC) Refer
to Charge
Air Cooler
Replacement
in SI
20162020
CAC Not
Frozen OR
Leaking and
no P0300
-
Refer to SI
20162019
CAC Not
Frozen OR
Leaking P0300
from driving in
humid/rainy
conditions
(Built Before
January 5,
2019) *
X
-
20162019
CAC Not
Frozen OR
Leaking P0300
from driving in
humid/rainy
conditions
(Built After
January 5,
2019) *
-
Refer to SI
5779438
Important: The latest designed charge air cooler is
wider, as shown in the picture above, and is NOT
compatible with the existing lower baffle on vehicles
built BEFORE January 5, 2019. The baffle will need to
be replaced to accommodate the larger charge air
cooler if the charge air cooler is being replaced
Chart Based Conditions
Model
Years
Condition
Repair Other
System Issue
Note: Replacement of the Charge Air Cooler is ONLY
required if GM IVH (View Vehicle Build) indicated build date
is Before January 5, 2019 AND GM IVH (View Transaction
History Detail) indicates the CAC has not been previously
replaced, or the part is damaged or leaking.
REPLACE
Charge Air
Cooler –
(CAC) Refer
to Charge
Air Cooler
Replacement
in SI
Repair Other
System Issue
-
Causal
Part
Description
X
Part
Number
X
Charge Air Cooler
84634949
N/A*
BAFFLE, RAD
AIR LWR
23350091
Parts Information
20162020
CAC Leaking
20162019
CAC Frozen
(Built Before
January 5,
2019) *
X
-
20192020
CAC Frozen
(Built After
January
5, 2019)
Thaw, clean
and
reinstall CAC
Refer to SI
20162020
CAC Frozen
AND Leaking
X
-
Qty
1
*For warranty transactions, DO NOT mark this/these
parts as the Causal Part. Enter the word "Bulletin" in
the Causal Part Description free-flow text field.
Bulletin No.: 21-NA-074
March, 2021
Page 3
Warranty Information
For vehicles repaired under the Powertrain coverage,
use the following labor operation. Reference the
Applicable Warranties section Of Investigate Vehicle
History (IVH) for coverage information.
Labor Operation
Description
Labor Time
4087008*
Perform Smoke Test for Charge Air Cooler and Charge Air
Cooler Replacement
2.3 hrs. (Envision)
*This is a unique Labor Operation for Bulletin use only.
Version
1
Modified
Released March 24, 2021
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION